1. Field of the Invention
The present invention relates generally to an electromagnetic interference (EMI)/radio frequency (RF) interference shielding gasket for use in suppressing undesired electromagnetic emissions. In particular, the present invention relates to an improved shielding gasket for reducing the amount of force required during the mounting process.
2. Background of the Invention
Electromagnetic interference (EMI) refers to an electromagnetic disturbance that may potentially impede or degrade the reception of authorized electronic emissions. Undesirable electromagnetic fields leaked from an electronic device may disrupt the operation of other electronic devices in a localized area. Although the metallic housing of the electronic device acts as a shield to contain electromagnetic signals, electromagnetic emissions may still pass through air gaps in the metallic enclosure seams. For example, enclosure seams, such as doors, panels, and other connected interfaces of a modular enclosure, may contain small gaps between modules. If an air gap exists in the seam, the flow of electromagnetic energy will be diverted to those connected interfaces and pass through the seam.
In order to contain or suppress undesired radiated emissions in modular enclosures, shielding gaskets are typically used to maintain a conductive pathway across enclosure members. For example, FIG. 1 depicts a known system 100 including EMI slot mount gasket 102. EMI gasket 102 comprises a plurality of ribs or clips, such as clips 104 and 106. Clips 104 and 106 act as latching mechanisms, and allow EMI gasket 102 to be mounted on flange 108 in a snap-on manner and hold EMI gasket 102 in place. Flange 108 may be located on a receiving device, such as a chassis member or a modular component. FIG. 1 illustrates how EMI gasket 102 may be mounted in slots of flange 108 and compressed between another chassis member or module 110 to effectively create a conductive pathway between the members.
EMI gaskets in effect seal the air gaps between mating modules or chassis members. With higher data rates exceeding frequencies of 1 gigahertz, the number of shielding gaskets used must be increased to reduce the size of apertures that might leak undesired EMI energy. Consequently, the application and installation of this increased number of shielding gaskets in a manufacturing environment becomes tedious and time consuming. Due to the difficulty in inserting the gaskets in their respective mounting holes or slots, the shielding gaskets may not be mounted correctly in many instances. Furthermore, slot mount gaskets may become damaged because of excess manipulation caused by the handlers in their attempts to position the gaskets by applying pressure to mount the ribs or clips into their respective slots. This excess manipulation may cause physical problems of employee thumbs and fingers, as well as cause failures in testing for radiated emissions if the gaskets are not mounted correctly. Excess handling of the gasket due to re-fitting may have corrosive effects that may deteriorate the conductivity of the material/plating surface over time (e.g., salt from fingertips if gloves are not worn). The corrosive effects may lead to early failure of the gasket joints, as well as causing the gasket to fall out of compliance with applicable agency regulations.
Therefore, it would be advantageous to have an EMI suppression mechanism that includes a lead-in to reduce the amount of force required of the assembler during the mounting process, thereby providing for easier assembly during rework or product upgrades.